Hyway MS460 big bore on a 044 opinions please

Lightning Performance · Dec 19, 2017

jacob j. said:
That may be the way to go. I know my 046 that's running an 064 piston with .050" machined out of the squish band is sure a good runner. You can run some taller numbers that way too.

I'm interested in building this set up.
What piston manufacturer are you using here?

drf256 · Dec 20, 2017

jacob j. said:
Machining the squish band inside the cylinder, the area around the combustion chamber. It makes a smaller combustion chamber and allows for a taller piston if you don't cut the base.

On my 046, the previous owner had ported it but not very well. His numbers were sloppy. I was able to correct that by having the squish band machined and running a taller piston.
It's now one of my favorite saws of all time. I loaned it to an Arborist buddy and he pieced down a
60" Spruce with it using a 36" bar.

Hey JJ,

What kinda compression are we talkin about here?

I know with 15 out, I’m at 200 psi

Did you mod it for a bigger chamber?

jacob j. · Dec 20, 2017

Lightning Performance said:
@jacob j.

I'm interested in building this set up.
What piston manufacturer are you using here?

It's running a Meteor piston that I bought from Diamond Dave's ebay store.

drf256 said:
Hey JJ,

What kinda compression are we talkin about here?

I know with 15 out, I’m at 200 psi

Did you mod it for a bigger chamber?

Al- in the neighborhood of 190ish. It has a little less static compression as the result of a tall exhaust port
(part of the bad porting numbers from the previous owner). I would say the exhaust duration is just over 170 degrees.

No work done to the chamber- it's a 460 jug with the round chamber.

drf256 · Dec 20, 2017

jacob j. said:
It's running a Meteor piston that I bought from Diamond Dave's ebay store.

Al- in the neighborhood of 190ish. It has a little less static compression as the result of a tall exhaust port
(part of the bad porting numbers from the previous owner). I would say the exhaust duration is just over 170 degrees.

No work done to the chamber- it's a 460 jug with the round chamber.

Thanks JJ.

A 95* ex roof would explain manageable compression.

MattG · Dec 21, 2017

jacob j. said:
I would say the exhaust duration is just over 170 degrees.

That thing must rev!

jacob j. · Dec 21, 2017

MattG said:
That thing must rev!

To the moon- it holds right at 11k in the cut but the amazing thing is, it doesn't care how much bar you have on it. It holds 11k whether it's a 20" bar or a 36". I've fell some big trees with it.

MattG · Dec 21, 2017

So people, I'm still thinking through my opinions for how to do this project. I got the hyway kit and yeah the piston has got depressingly short skirts. @J_M____ did reckon that there's a longer skirt huztl 54mm piston. To be honest I'd sooner go OEM, but haven't found anything suitableyet. The 066 slug is about 1.5mm too big pin-to-crown as CFB's pic reveals:

So guys - anyone have experience of machining the top of an OEM piston? Would it be acceptable to shave off up to 1mm off the top of one? Or would that make the OEM piston as bad as a new Huztl?!!!

Lightning Performance · Dec 21, 2017

Gtg saw is the plan. The lightest piston possible.

I did one of those hundred foot spruce trees. Chunking down with a 361 20" to 660 28" es is no joke. A 044 wearing a light 36" would be much better for me!

Lightning Performance · Dec 21, 2017

MattG said:
So people, I'm still thinking through my opinions for how to do this project. I got the hyway kit and yeah the piston has got depressingly short skirts. @J_M____ did reckon that there's a longer skirt huztl 54mm piston. To be honest I'd sooner go OEM, but haven't found anything suitableyet. The 066 slug is about 1.5mm too big pin-to-crown as CFB's pic reveals:

reveals.

So guys - anyone have experience of machining the top of an OEM piston? Would it be acceptable to shave off up to 1mm off the top of one? Or would that make the OEM piston as bad as a new Huztl?!!!

Your knocking on the ring of death driving the piston that far up. The top will get thin if you dont put a dome on it.

Lightning Performance · Dec 21, 2017

drf256 said:
Hey JJ,

What kinda compression are we talkin about here?

I know with 15 out, I’m at 200 psi

Did you mod it for a bigger chamber?

Where should I draw the line on compression for a full time gtg saw?
It might chunk something big once in a while. I know the case is going to need some mods, volume mainly.

MattG · Dec 21, 2017

Lightning Performance said:
Your knocking on the ring of death driving the piston that far up. The top will get thin if you dont put a dome on it.

Yeah, I did suspect that to be the case.

So when people do a "pop up piston", presumably they leave the center unmilled right? And just lathe the piston below the squish........so how much approximately do they "safely" lathe off when making a popup?

Lightning Performance · Dec 21, 2017

MattG said:
Yeah, I did suspect that to be the case.

So when people do a "pop up piston", presumably they leave the center unmilled right? And just lathe the piston below the squish........so how much approximately do they "safely" lathe off when making a popup?

Ever piston varies. Weight, heat, crown structure and so much more. My main concern would be expansion of the top. Most guys miss this stuff and seize the piston. Mill the side too. You'll thank me later.

mdavlee · Dec 21, 2017

Leave .100" from crown to ring land.

mdavlee · Dec 21, 2017

MattG said:
That thing must rev!

Transfers make more of a difference than exhaust. 95 is a normal exhaust height for me to use in my stuff.

MattG · Dec 21, 2017

mdavlee said:
Leave .100" from crown to ring land.

Thanks mate!

MattG · Dec 21, 2017

mdavlee said:
Transfers make more of a difference than exhaust. 95 is a normal exhaust height for me to use in my stuff.

Sure I guess all engines have subtly differing characteristics, my best experience in this game is the 044/460 I just finished, after tossing out the BG and machining back 0.024" squish, I didn't change the transfers (122), only the exhaust (now 101) inlet (77) and it revs like a madman! 4-strokes at just about 15.2k still I reckon!

mdavlee · Dec 21, 2017

MattG said:
Sure I guess all engines have subtly differing characteristics, my best experience in this game is the 044/460 I just finished, after tossing out the BG and machining back 0.024" squish, I didn't change the transfers (122), only the exhaust (now 101) inlet (77) and it revs like a madman! 4-strokes at just about 15.2k still I reckon!

Even with 103 exhaust I've had them 4 stroke to over 16k

MattG · Dec 21, 2017

mdavlee said:
Even with 103 exhaust I've had them 4 stroke to over 16k

To be honest my ears have packed up and gone home by about 15.5K !!!

drf256 · Dec 21, 2017

Lightning Performance said:
Where should I draw the line on compression for a full time gtg saw?
It might chunk something big once in a while. I know the case is going to need some mods, volume mainly.

Debatable Topic

I'd say 210 for a worksaw max. Others may not agree.

Lightning Performance · Dec 22, 2017

drf256 said:
Debatable Topic

I'd say 210 for a worksaw max. Others may not agree.

And the great debate rages on...
I was considering 225. That should allow wiggle room to open the chamber if it is too much.

Is anyone running more than 220 in gtg saws of this model? Just looking for max grunt without wasting power/rpm. Im not worried about wear and tear. This will not be a daily driver
All my jugs are round chamber.

Hyway MS460 big bore on a 044 opinions please

Here For The Long Haul!

Dr. Richard Cranium

Lord of Cargo Pants

Dr. Richard Cranium

Chainosaurus Rex

Lord of Cargo Pants

Chainosaurus Rex

Here For The Long Haul!

Here For The Long Haul!

Here For The Long Haul!

Chainosaurus Rex

Here For The Long Haul!

Hillbilly grinder

Hillbilly grinder

Chainosaurus Rex

Chainosaurus Rex

Hillbilly grinder

Chainosaurus Rex

Dr. Richard Cranium

Here For The Long Haul!

Similar threads